Folks - I'm new to dirtrider.net. I was tempted to start this thread on the "mods" forum but upon reading Eric Gorr's sticky I decided to take a chance and start the thread in this forum. My apologies if I'm totally out of place by placing this here.
I looked for a good way to get my 8-yr old from a 50 4-stroke to a 2-stroker mxer, clutch and all, without scaring 'em to death and a used Suzuki JR80 is working rather well. He took to it really well and very quickly. It's exciting to hear him get the thing up on the pipe (I used to race an RM back in the early '80s) 'cause he's figured out that's where the power is. In fact, he seems to be lookin' for more!!! Quite a surprise, really, he seemed a little timid when he got the Honda 50 last summer.
I'm going to hold off on a RM/KX/SX-65 for a year or so to build up his confidence and skills. This bike is nice and easy through the trails in our woods but can rev up pretty nicely too. However, there's a few things I thought you might have some ideas on:
1) It bogs some at low RPM when he gets a slow start and throttle response is slow at low range (he does strongly prefer, however, to blow dirt/gravel all over the place instead!). When this happens he jams the throttle wide open but it still takes several seconds before RPMs pick up, then it'll be fine. It's not bad at all as he's rounding a corner and at least moving just a bit, just "off the line". I read where this happens simply because it's a JR80 - a detuned mx bike - and that fmf makes a fatty that helps out a bunch. I do like the fact that he doesn't get the big hit he would with a real mxer - maybe the bogging is the price to pay for this. I took apart the carb and cleaned it thoroughly - that helped a little. Air filter is clean ('could open her up a bit, though) I replaced the rear sprocket moving from a 34-tooth to 36-tooth and it helped even more. He's getting better with the clutch and this helps too. I'd just like to see the thing rev up a little faster. I'm considering a different airbox w/ rejetting. Your thoughts?
2) The bike smokes a bit. It's not excessive but I'd like to get it right if possible. I thoroughly cleaned the baffle/SA and after about 6 hours of riding it has some wet gunk in it. The spark plug doesn't foul so I don't believe it's as bad as a crankcase seal (at least I hope). Does this problem go hand-in-hand with the bogging? Like, maybe it's a little rich, I'm thinking, but I wanted some opinions before I start rejetting. It's got a Mikuni 20mm round slide and I've got the main and pilot sizes so I'm getting ready to order a few smaller and a few larger of each and get crackin'. Any comments or suggestions?
We're having a blast but I'm looking ahead. We're not trying to be competitive with real MX bikes (I hope he doesn't find out what I just wrote) just trying to get what we can out of it. I know there's limitations but the closer I get to a 65 mxer the more fun it will be when I get one for him! I mentioned that the hit on an mxer might be too intimidating but some of the hit would be OK. So, thanks ahead of time for your feedback.
I looked for a good way to get my 8-yr old from a 50 4-stroke to a 2-stroker mxer, clutch and all, without scaring 'em to death and a used Suzuki JR80 is working rather well. He took to it really well and very quickly. It's exciting to hear him get the thing up on the pipe (I used to race an RM back in the early '80s) 'cause he's figured out that's where the power is. In fact, he seems to be lookin' for more!!! Quite a surprise, really, he seemed a little timid when he got the Honda 50 last summer.
I'm going to hold off on a RM/KX/SX-65 for a year or so to build up his confidence and skills. This bike is nice and easy through the trails in our woods but can rev up pretty nicely too. However, there's a few things I thought you might have some ideas on:
1) It bogs some at low RPM when he gets a slow start and throttle response is slow at low range (he does strongly prefer, however, to blow dirt/gravel all over the place instead!). When this happens he jams the throttle wide open but it still takes several seconds before RPMs pick up, then it'll be fine. It's not bad at all as he's rounding a corner and at least moving just a bit, just "off the line". I read where this happens simply because it's a JR80 - a detuned mx bike - and that fmf makes a fatty that helps out a bunch. I do like the fact that he doesn't get the big hit he would with a real mxer - maybe the bogging is the price to pay for this. I took apart the carb and cleaned it thoroughly - that helped a little. Air filter is clean ('could open her up a bit, though) I replaced the rear sprocket moving from a 34-tooth to 36-tooth and it helped even more. He's getting better with the clutch and this helps too. I'd just like to see the thing rev up a little faster. I'm considering a different airbox w/ rejetting. Your thoughts?
2) The bike smokes a bit. It's not excessive but I'd like to get it right if possible. I thoroughly cleaned the baffle/SA and after about 6 hours of riding it has some wet gunk in it. The spark plug doesn't foul so I don't believe it's as bad as a crankcase seal (at least I hope). Does this problem go hand-in-hand with the bogging? Like, maybe it's a little rich, I'm thinking, but I wanted some opinions before I start rejetting. It's got a Mikuni 20mm round slide and I've got the main and pilot sizes so I'm getting ready to order a few smaller and a few larger of each and get crackin'. Any comments or suggestions?
We're having a blast but I'm looking ahead. We're not trying to be competitive with real MX bikes (I hope he doesn't find out what I just wrote) just trying to get what we can out of it. I know there's limitations but the closer I get to a 65 mxer the more fun it will be when I get one for him! I mentioned that the hit on an mxer might be too intimidating but some of the hit would be OK. So, thanks ahead of time for your feedback.
